RU2266391C1 - Device for pipe liner installation and sealing in well - Google Patents

Abstract

FIELD: equipment for oil and gas well casing, particularly device for casing pipe lowering and casing pipe annuity sealing.

SUBSTANCE: device comprises hollow sectional body, disconnector and conveying string connected to the disconnector. Device also comprises packer secured to disconnector in upper part and to anchor in lower part thereof. Pipe liner is made as filtering column provided with perforated grouting mortar displacement fitting in upper part thereof. Drillable plug is installed between pipe liner and perforated fitting. Drillable shutoff valve assembly is arranged in lower body section part between anchor and perforated fitting. The shutoff valve assembly comprises check valve, baffle collar and bush connected to baffle collar by shear pin. The bush cooperates with ball to be thrown into conveying string. The bush cooperates with two-sectional top plug. Lower section of sectional top plug has through channel and connected to disconnector by shear pin. Disconnector is installed in upper body section and may be rotated to cooperate with it without performing lengthwise movement. The disconnector is secured to press-on packer bush by left-handed thread. The press-on bush is installed on upper body section and may perform lengthwise movement. The press-on packer is connected with upper body section by key joint.

EFFECT: increased operational reliability.

1 dwg

Description

The invention relates to the field of attachment of oil and gas wells, and in particular to devices for lowering and sealing the annular space of the casing strings and, in particular, the casing stems.

A device for suspension and sealing a casing collar, including:

- hollow body

- a disconnector connected to the housing with a left-hand thread, on the shaft surface of which external slots are made;

- a packer of push action, the elastic seal of which interacts with a sleeve movably mounted on the housing and interacting with internal slots with the external slots of the disconnector;

- hydraulic anchor,

- a two-section squeezing plug, the lower section of which has a through channel and is connected by a shear pin to the disconnector, and the upper section interacts with the lower section after the device with a countersunk casing is lowered into the well;

- and a landing sleeve with a stop ring interacting with the cork stopper (RF Patent No. 2206713, Е 21 В 33/14, 17/06).

A disadvantage of the known device is the low reliability of operation, due to the fact that for the operation of the mechanical packer of the push action, it is necessary that the outer slots of the disconnector body connected to the drill string, after rotation of the latter by an arbitrary number of revolutions, are guaranteed to be shifted relative to the internal splines of the packer sleeve. In the absence of angular displacement and coincidence of the slots, the disconnector shaft when lowering the drill string will re-enter the packer sleeve, and the subsequent unloading of the drill string will occur along the initial turns of the internal thread of the device body and the external thread of the shaft. This will inevitably lead to their crushing and the impossibility of subsequent make-up, for example, to remove the device to the surface. Thus, it is possible that the packer sleeve will not move downward, compressing the seal, and the design of the known device does not allow to control this on the surface. Since the fact of the packer’s failure and annular space leakage can be detected only after the OZC by jointly crimping the secret and previously lowered casing strings, eliminating these consequences arising from the low reliability of the known device will require considerable labor and time.

In addition, the known device has limited operational capabilities, since it is applicable only with countersunk casing to eliminate leaks in a previously lowered casing and cannot be used as a device for installing and sealing a casing string, made, for example, in the form of a filter located in horizontal the well section is usually open, i.e. not cemented grouting mortar.

A device for installing and sealing a liner casing in the well, including:

- a housing, a transport column connected thereto, a disconnector, a packer and an anchor located in the upper part of the shank,

- a pipe connected with the housing with radial holes, forming an annular cavity with a shank in its upper part, hydraulically connected to the pipe cavity through its radial holes and with the drive units of the armature, packer and disconnector,

- a throttle-shutoff valve connected to the shank and located under the radial openings to shut off the internal section of the pipe at a given flow rate with predetermined rheological properties, including a cylindrical bushing with a seating seat in the lower part and a rod spring-loaded relative to the bushing and forming an annular calibrated channel with it,

- moreover, the pipe is made with the possibility of its extraction from the well with the body and the transport column, and the liner under the device is made in the form of a filter column with holes in the upper part for displacing cement slurry (RF Patent No. 2171366, E 21 V 43/10, 33/14 )

A disadvantage of the known device is the low reliability associated with the following circumstances:

a) it is well known that any fluids injected into the well (drilling and grouting solutions, buffer fluid, etc.) have various foreign inclusions in their volume, including: sludge and pieces of stale cement, fragments of metal and wood, and finally, fabric fragments of the shelter of the drilling rig, mittens and overalls. All this, in the composition of the pumped liquids from the tanks of the circulation system, can enter the transport column and then into the cavity of the nozzle of the known device, at the end of which there is a butterfly valve with an annular calibrated channel. Any of the listed inclusions with dimensions slightly exceeding the gap in the annular calibrated channel, which, under the force of the pressure drop, falls into this gap, may get stuck in it and prevent the throttle-shut-off valve from closing, which will make it impossible to increase the pressure in the nozzle cavity and failure of the mechanisms of the disconnector, packer and anchor;

b) to operate the throttle shut-off valve, it is necessary to pump liquid (cement slurry) with the specified rheological properties through a known device. And this is quite laborious to ensure on the surface even by preliminary leveling the properties of the cement slurry in its entire volume, sometimes reaching several tens or even hundreds of cubic meters, since for this it is necessary to have a certain number of tanks with hydraulic and mechanical mixers on the surface. Operating time for thorough mixing of the entire volume of liquid may take several hours. Since the process of preparing cement slurry is limited by the time factor due to its setting, it is possible that the required rheological properties will not be obtained in the entire volume of cement slurry. Therefore, in the case when a certain volume of solution with slightly different properties, for example, with a higher viscosity and specific gravity, is pumped through the throttle shutoff valve, this will lead to the closing of the throttle shutoff valve and premature operation of the disconnector, packer and anchor mechanisms.

In addition, the automatic, without a command from the surface, the operation of the disconnector, packer and anchor mechanisms does not provide the ability to control these processes.

The combined effect of these circumstances will lead to the fact that the device will not be able to fulfill its purpose, as a result of which there will be a need to quickly remove it from the well to prevent an accident in the form of a sticking, and then after drilling the cement nozzle remaining in the well, repeat the installation and sealing of the casing liner in well.

Thus, the low reliability of the known device can lead to a significant increase in costs during its operation.

The objective of the invention is to provide a device for installing and sealing a liner casing, devoid of the above disadvantages.

The technical result of solving this problem is to increase the reliability of the device for installing and sealing the liner of the casing string and, as a consequence, to increase the reliability of sealing the annulus over the liner.

To ensure these results, a known device for installing and sealing a casing liner, including:

- hollow sectional housing,

- the disconnector and the associated shipping column,

- a packer in the upper part connected to the disconnector, and in the lower part with the anchor,

- moreover, the shank under the device is made in the form of a filter column, in the upper part of which there is a perforated pipe for displacing the cement slurry,

ACCORDING TO THE INVENTION

- additionally contains a drillable plug installed between the shank and the perforated nozzle,

- and a drillable valve-locking assembly installed in the lower section of the housing between the armature and the perforated nozzle and including

- check valve

- a landing sleeve interacting with a two-section screw-in plug, the lower section of which has a through channel and is connected by a shear pin to the disconnector;

- a landing sleeve connected to the landing sleeve with a shear pin and interacting with a ball discharged into the transport column,

- moreover, the disconnector is mounted on the upper section of the housing with the possibility of rotation, interacting with it without longitudinal movement, and is connected by a left-hand thread to the presser sleeve of the packer, which is mounted on the upper section of the housing with the possibility of longitudinal movement and connected with it by a key connection.

The drawing shows a General view of the device (in the initial position before the descent into the well).

The device comprises a hollow sectional housing 1, consisting of an upper section 2, a middle section 3 and a lower section 4. On the upper section 2, a disconnector 5 is mounted for rotation without longitudinal movement, in the lower part of the axial channel 6 of which there is a lower section 7 of the cork plug, which has a through channel 8 and is connected by a shear pin 9 to the disconnector 5. In the upper part, the disconnector 5 is connected to the transport column 10, into which, after lowering the device into the well, the upper section 11 of the flow plug .

The upper section 2 of the housing 1 together with the seal 12 made of elastic material and the pressure sleeve 13 are included in the packer 14. The pressure sleeve 13 is connected to the disconnector 5 by the left-hand thread 15 and is connected to the upper section 2 of the housing 1 by a key connection 16, so that it relative to the housing 1, only longitudinal movement is possible (principle of a screw jack). To reduce friction during rotation of the disconnector 5 between the lower end and the end of the upper section 2 of the housing 1 is installed thrust bearing 17.

The middle section 3 and the lower section 4 of the housing 1 together with the piston 18 and the wedge dies 19, interacting with the wedge guides 20 made on the middle section 3, are part of the armature 21. In the initial position, the piston 18 is connected to the lower section 4 of the housing 1 by a shear pin 22 and forms with it in the lower part an annular cavity 23 associated with the cavity 24 of the housing 1 by the hole 25.

A valve-locking unit 26 is attached to the lower part of the housing 1 from the bottom, including a mounting sleeve 28 installed in the sub 27, in which a mounting sleeve 29 for the messenger ball 30 is located, connected to the sleeve 28 with a shear pin 31, a grill 32 and a check valve 33. the pressure required to cut the pin 31 exceeds the pressure required to cut the pin 22.

A perforated pipe 35 is attached to the lower end of the sub 27 by inserting the required length from the pipes 34, under which a drillable plug 36 is connected, connected to the shank 37. The length of the pipes 34 is selected so that the shank 37 in the form of a filter string is located in the open borehole in the interval productive formation (not shown), operated by an open method, and the upper part of the inventive device, located above the pipes 34, was located in the casing (not shown).

The inventive device operates as follows.

In the position shown in the drawing, the device without the upper section 11 of the cork plug and messenger ball 30 on the transport column 10 is lowered into the well, periodically producing liquid being added to the pipes of the column 10. After installing the liner 37 in the required interval, the messenger ball 30 is dropped into the column 10, which, after landing on the saddle of the landing sleeve 29, separates the cavity 24 of the housing 1 from the cavity of the sub 27 located under the landing sleeve 29. Then, on the surface, turn on a pump (not shown), pumping liquid and increasing the pressure in lonne 11 and associated cavity 24 of the housing 1.

At the same time, pressure will increase in the annular cavity 23 formed by the lower section 4 and the piston 18 and connected to the cavity 24 by the hole 25, and a force will be created that acts on the piston 18. At a certain magnitude of this force, the pin 22 and the piston 18 of the armature 21 are cut off. moving up, it will move the dies 19 connected to it along the wedge guides 20 of the lower section 4, pushing the dies 19 beyond the outer diametric dimension of the housing 1 until it contacts and engages with the inner surface of the casing metal pipe. With further injection of fluid and increasing pressure on the sleeve 29 of the valve-locking unit 26, a force appears that cuts the pin 31. The sleeve 29, moving down into the cavity of the grating 32, will allow the pumped fluid to circulate through the hole of the landing sleeve 28, the holes of the grate 32, the squeeze hole down the check valve 33 and the hole of the pipe 35 into the wellbore.

On the surface, the cutoff time of pins 22 and 31 and the activation of the armature 21 will be marked by an increase in pressure on the manometer that registers the pressure of the pumped fluid into the transport column 10, and the movement of the sleeve 29 and the hydraulic communication of the cavity 24 of the housing 1 and the wellbore will be marked by a pressure drop and fluid circulation from the well. Next, the conveyor string 10 and the housing 1, connected to the latter by the disconnector 5, are lowered downward relative to the fixed dies 19, checking the reliability of the operation of the armature 21. At the same time, the adhesion of the dies 19 to the casing pipe increases, since when the casing 1 is moved down, and therefore , and located on the middle section 3 of the wedge guides 20, the latter, acting on the wedge dies 19, will increase the force of their penetration into the wall of the casing pipe.

Thus, the additional supply of the claimed device valve-locking unit 26 provides the ability to control the process of operation of the armature 21, which increases the reliability of the claimed device compared to the prototype.

Subsequent pumping from the surface of the required volume of cement slurry produces cementing of the wellbore in the interval from the reservoir, i.e. from the shank 37 to the upper part of the claimed device, i.e. to the upper end of the disconnector 5. After the cement slurry is injected into the transport column 10, the upper section 11 of the squeeze plug is sent and moved by pumping buffer fluid through the column 10 until it is planted in the lower section 7 of the squeeze plug. In this case, the grouting fluid is displaced by the upper section 11 from the transport column 10 through the axial channel 6 of the disconnector 5, the through channel 8 of the lower section 7, the cavity 24 of the housing 1, the hole of the landing sleeve 28, the holes of the grill 32, the hole of the check valve 33 pressed down and the holes of the pipe 35 into the wellbore. At the same time, plug 36 will prevent the cement slurry from entering the cavity of the liner 37, made in the form of a filter column, and, therefore, into the interval of the productive formation of the open wellbore, which will allow to preserve the permeability of the reservoir and increase the flow rate of the well.

After the sections 11 and 7 of the flow plug are joined and the through channel 8 is closed in the transport column 10 and the axial channel 6, an increase in pressure will occur, the pin 9 will be cut off by force. Then the combined flow plug, consisting of sections 11 and 7, displacing the grouting mortar from cavity 24 of the housing 1 will move down to the dock with the landing sleeve 28, blocking its channel. As a result of this, pressure will increase in the transport column 10 and in the cavity of the housing 1, which will be recorded on the surface by a pump pressure gauge pumping liquid into the transport column 10, as a result of which the pump is turned off.

For more reliable sealing of the annular space between the device and the casing, the packer 14 is activated, for which purpose the transport column 10 with the disconnector 5 are rotated clockwise. As a result of this, the pressure sleeve 13 connected to the disconnector 5 by the left-hand thread, and with the key connection 16 to the upper section 2 of the housing 1, will be screwed from the disconnector 5 and longitudinally move downward, compressing the elastic seal 12. The seal 12, expanding, will come into contact with the wall casing string, displacing cement slurry from the annular space between the seal 12 and the wall of the casing string. In this case, the perception of the axial force from the weight of the transport column 10 during the rotation of the disconnector 5 and the reduction of friction on the interacting ends of the last and upper sections 2 of the housing 1 is carried out by a thrust bearing 17. In this case, the process of moving the push sleeve 13 downward while rotating the disconnector 5 will be recorded on the surface reducing the weight indicator of the transport column 10. This allows you to control how the compression process of the seal 12, i.e. the operation of the packer assembly 14, and the process of disconnecting the transport column 10 from the inventive device, i.e. actuation of the disconnector assembly 5. After the screw sleeve 13 is fully screwed from the disconnector 5, they will be disconnected, which is controlled by lifting the transport column 10 with the disconnector 5 up and increasing the weight indicator.

Thus, the introduction into the packer assembly 14 of the pressure sleeve 13 connected to the disconnector 5 by the left-hand thread and to the upper section 2 of the housing 1 by the key connection 16 ensures both the simultaneous processes of disconnecting the transport column 10 from the device and the actuation of the packer assembly 14. Moreover, these processes are controlled on the surface, which increases the reliability of the claimed device compared to the prototype.

By turning on the pump surface, the fluid is circulated through the transport column 10, washing away the remains of cement slurry above the device, after which the transport column 10 with disconnector 5 is removed from the well.

Then, after the cement slurry has solidified and cement stone has formed in the annular space between the device and the wellbore, a drill string with a bit is lowered into it and drill plug sections 11 and 7, fit sleeve 28, fit sleeve 29, grate 32, check valve 33 and plug 36, ensuring the connection of the cavity 24 of the housing 1 with the cavity of the liner 37. After that, the drill string with a bit is removed from the well.

Thus, the set of distinctive features of the claimed device provides, in comparison with the prototype, the possibility of real-time monitoring of the operation of all nodes of the device and operational control from the surface of all operations for installing the device in the well, which improves the reliability of the claimed device.

Claims (1)

A device for installing and sealing a casing liner, including a hollow sectional casing, a disconnector and a transport column connected thereto, a packer connected to the disconnector in the upper part and an anchor in the lower part, and the liner is made in the form of a filter column in the upper part which has a perforated nozzle for displacing cement slurry, characterized in that it further comprises a drillable plug installed between the shank and the perforated nozzle, and a valve-locking assembly installed in the lower section of the housing between the armature and the perforated nozzle and including a non-return valve, a seat coupling interacting with a two-section bushing plug, the lower section of which has a through channel and is connected by a shear pin to the disconnector, and a bushing connected to the bushing coupling shear pin and interacting with a ball discharged into the transport column, and the disconnector is mounted on the upper section of the housing with the possibility of rotation, interacting it without longitudinal movement, and left-hand thread is connected with the pressing sleeve of the packer which is mounted on the upper body section to move longitudinally and is connected with its keyed connection.